what the hell is a nug i keep hearin people say it but i dunno what it means. im good on most other words its just this one i got trouble with.
1 Improper use of contact lenses or steroid eyedrops can lead to fungal infections, which in turn can cause corneal ulcers. Also, a corneal injury that results in plant material getting into the eye can lead to fungal keratitis.  Acanthamoeba are microscopic, single-celled amoeba that can cause human infection.
In many cases, the reason for mouth ulcers is unclear. Most single mouth ulcers are caused by damage to the lining inside of the mouth. For example: accidentally biting the inside of your cheek or a sharp tooth.